Lesson 11

Dividing Rational Numbers

Let's divide signed numbers.

Problem 1

Find the quotients:

  1. \(24 \div \text-6\)
  2. \(\text-15 \div 0.3\)
  3. \(\text-4 \div \text-20\)

Problem 2

Find the quotients.

  1. \(\frac25 \div \frac34\)
  2. \(\frac94 \div \frac {\text{-}3}{4}\)
  3. \(\frac {\text{-}5}{7} \div \frac {\text{-}1}{3}\)
  4. \(\frac {\text{-}5}{3} \div \frac16\)

Problem 3

Is the solution positive or negative?

  1. \(2\boldcdot x=6\)
  2. \(\text-2\boldcdot x=6.1\)
  3. \(2.9 \boldcdot x = \text-6.04\)
  4. \(\text-2.473\boldcdot x = \text-6.859\)

Problem 4

Find the solution mentally.

  1. \(3 \boldcdot \text-4 = a\)
  2. \(b \boldcdot (\text-3) = \text-12\)
  3. \(\text- 12 \boldcdot c = 12\)
  4. \(d \boldcdot 24 = \text-12\)

Problem 5

In order to make a specific shade of green paint, a painter mixes \(1\frac12\) quarts of blue paint, 2 cups of green paint, and \(\frac12\) gallon of white paint. How much of each color is needed to make 100 cups of this shade of green paint?

(From Unit 4, Lesson 2.)

Problem 6

Here is a list of the highest and lowest elevation on each continent.

highest point (m) lowest point (m)
Europe 4,810 -28
Asia 8,848 -427
Africa 5,895 -155
Australia 4,884 -15
North America 6,198 -86
South America 6,960 -105
Antartica 4,892 -50
  1. Which continent has the largest difference in elevation? The smallest?
  2. Make a display (dot plot, box plot, or histogram) of the data set and explain why you chose that type of display to represent this data set.
(From Unit 5, Lesson 3.)